r262154 - in /branches/gcc-8-branch/gcc: Change...

[segher@gcc.gnu.org]

Author: segher
Date: Tue Jun 26 15:36:21 2018
New Revision: 262154

URL: https://gcc.gnu.org/viewcvs?rev=262154&root=gcc&view=rev
Log:
regcprop: Avoid REG_CFA_REGISTER notes (PR85645)

Changing a SET that has a REG_CFA_REGISTER note is wrong if we are
changing the SET_DEST, or if the REG_CFA_REGISTER has nil as its
argument, and maybe some other cases.  It's never really useful to
propagate into such an instruction, so let's just bail whenever we
see such a note.


	Backport from trunk
	2018-05-08  Segher Boessenkool  <segher@kernel.crashing.org>

	PR rtl-optimization/85645
	*  regcprop.c (copyprop_hardreg_forward_1): Don't propagate into an
	insn that has a REG_CFA_REGISTER note.

Modified:
    branches/gcc-8-branch/gcc/ChangeLog
    branches/gcc-8-branch/gcc/regcprop.c